1. Field of the Invention
This invention relates to a bubbler device for washing semiconductor materials (wafers) set in a carrier within a rinse vessel.
2. Description of the Prior Art
Usually, in the process of producing semiconductor wafers, a suitable number of wafers, for example 25 to 50 sheets as one lot, will be treated and those wafers housed in a carrier will be washed. In a commonly accepted technique, the apparatus for washing semiconductor wafers set in a carrier, for example, such as shown in FIGS. 6-8, is known. This sort of apparatus includes a rinse vessel, in which pure water or chemical liquid is introduced, and a bubbler device located on the bottom of the vessel, as shown in FIG. 6. A carrier including a series of semiconductor wafers therein is set within the rinse vessel by means of an arbitrary supporting frame, and the bubbler serves to stir the liquid within the rinse vessel so as to facilitate contacts between the respective wafers and the liquid for washing the wafers.
Such a bubbler device, as shown in FIG. 7, consists of a main pipe which connects to a gas feeding apparatus, a suitable number of branch pipes which branch off from the main pipe and the bubbling portions located on the end of the respective branch pipes for the generation of bubbles. These constituent parts are made of fluorine resin or quartz, etc. Each bubbling portion is integrally formed with the branch pipe which is fastened to the main pipe by means of welding or adhesion so that they are integrally formed. The respective bubbling portions are formed with many fine holes.
These conventional bubbler devices described above have some drawbacks and problems as will be pointed out below. Since the bubbling portion has many fine holes formed thereon through which bubbles are generated, the liquid in the rinse vessel will enter the respective bubbling portions and the pipes through these holes. Accordingly, a quantity of the liquid will be contained in the bubbler device, so that it reduces the gas passages in the pipes to thereby hinder the gas flow. Also, bacteria will occur in the liquid held within the bubbler device, which results in contamination of the liquid. Otherwise, if there is a difference in height between both sides of the bubbling portions, the liquid held in the bubbler will block up the fine holes of the bubbling portions on one side which then can not generate bubbles.